I have been using the notched "I call them tracks" as some are music and others are white noise, or Rain. My T hit me in Sept of 2015 after having "Radio Frequency" killing the sensory nerve on 4 of my vertebrae on both sides. Since that time I have tried just about everything. My T does not stay in one place, it will travel all over, above my ear(s), top of my head, back of head near the spine, front lobe of my brain. I can wake up in the morning and it will be as low as 2 out of 10, and before the day is done it will be at a 7 or 8 out of 10. I have mounted two speaker to my headboard so I can play the notched music all night. That is when tracks seem to do the most good. The audiologist "four of them" all told me they could not give me a definite frequency for my T, only a range which is 4000Hz, 5000Hz, to 6000Hz. The one audiologist indicated that the T was closest to 6000Hz so this is what I have been primarily directing my tracks to. Lately I have made four tracks, one for each frequency, plus one at 7000Hz as it seems like my T has changed frequencies. I have them on my mp3 player in order of 7,6,5,4khz and have the mp3 set to repeat play on each of them. When I got up this morning my T was at the lowest it has been. It has stayed that way for most of today. I might add that starting 4 days I also went to a hypnotist who specializes with T suffers, and also started the Emotional Freedom Technique. I don't know how much of an effect the last two have had, but I will continue with them for now. The hypnotist gave me a relaxing routine which I am trying to implement, not sure how well this is working, only been at it for a few of days.
I tried the neuromodulation, but you are right this seems to go just the opposite direction, so I have not done much with it. I used Audacity to make the modulation and notched tracks but didn't really like them. Unable to find much on YouTube for 6000Hz Tinnitus in either music or modulation so I just got music and made my own. There another notch app that is called "Band Stop Filter" which takes out a much wider notch than the "Notch Filter" Not sure if any of this answers you questions, or helps, but I hope it does.
Ragman